Co-hydrothermal treatment of chicken carcass and non-animal biomass for cleaner production

Abstract

To determine the feasibility of co-hydrothermal treatment to achieve cleaner production of chicken carcass (CC), we selected six non-animal biomasses (wheat straw (WS), bamboo sawdust (BS), wheat straw-derived pyrolytic char (WC), bamboo sawdust-derived pyrolytic char (BC), sewage sludge (SS), and food waste (FW)) for co-hydrothermal treatment with CC. The results showed that CC and FW yielded the greatest synergistic effect on bio-oil production with a synergistic coefficient of 25.20 %, while co-hydrothermal treatment of CC and WS resulted in the maximum yield of bio-oil (51.25 %). CC and BC achieved the greatest synergistic effect on hydrochar formation, with a maximum yield of 54.16 wt%. Moreover, the interaction between CC and all other biomasses reduced the release rate of ammonia in gas products, wherein the interaction between BS and CC promoted nitrogen immobilization in hydrochar with a maximum synergistic coefficient of 395.53 %. The co-hydrothermal treatment enhanced the deoxygenation reaction, resulting in hydrochars with lower oxygen-carbon ratios and higher heating value. The co-hydrothermal treatment also could facilitate the preparation of uniform and regular carbon microspheres, increase the specific surface area and enhance the adsorption capacity of copper ions of hydrochar, elevate the ignition point temperature of hydrochar to reduce the risk of fire during transport and storage, and expand the combustion temperature range of hydrochar. Additionally, the bio-oil obtained from co-hydrothermal treatment of CC and FW exhibited the best combustion performance with the highest comprehensive combustion index of 7.24 °C⁻³·min⁻².